使用GDI+在屏幕上绘制一幅图片，并支持鼠标移动。

使用picture控件很容易，GDI+也和控件一样的原理：
窗体初始化时记录图片左上角点坐标（全局私有变量），鼠标Down时记录起始的鼠标坐标，然后再鼠标Up时，用图片原来的左上角点坐标加上当前鼠标位置，然后再减去Down时的鼠标位置，即得到新的图片左上角点位置。

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    private Image  bmp;
    private int x, y;
    private Point[] bmpBounds;

    private Point orgPoint;
    private Rectangle bmpRect;

    public Form1()
                {
                        InitializeComponent();
                        bmp = Image.FromFile("1.jpeg");
                        x = 0;
                        y = 0;
                        bmpBounds = new Point[3];
                        bmpBounds[0] = new Point(x, y);
                        bmpRect = new Rectangle(x,y,bmp.Width ,bmp.Height );
                }      

     protected override void OnPaint(PaintEventArgs e)
                {
                        base.OnPaint(e);
                        Graphics g = e.Graphics;
                        g.ScaleTransform(1.0f, 1.0f);
                        g.DrawImage(bmp,bmpRect );
                        g.Dispose();
                }

   private void Form1_MouseDown(object sender, MouseEventArgs e)
   {
        if (e.Button == MouseButtons.Left)
        {
                orgPoint = new Point(e.X, e.Y);
        }      

  }

        private void Form1_MouseUp(object sender, MouseEventArgs e)
        {
                if (e.Button == MouseButtons.Left)
                {
                        bmpBounds[0].X = bmpBounds[0].X + e.X - orgPoint.X;
                        bmpBounds[0].Y = bmpBounds[0].Y + e.Y - orgPoint.Y;
                        bmpRect = new Rectangle(bmpBounds[0].X, bmpBounds[0].Y, bmp.Width, bmp.Height);
                        this.Invalidate();
                }

        }
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如果使用picturebox控件的话，将Down事件换为Move事件效果似乎更好。